Geocaching is an entertaining adventure game for GPS (Global Positioning System) users. The basic idea is to have people hide caches (containers of misc. goodies) all over the world and share the coordinates of these caches on the Internet. Players can then use the coordinates to find the caches. Once found, a cache may provide the visitor with a wide variety of rewards. There are more than 30,000 caches in over 140 countries. Read all about it at Geocaching.com.